Certain chemical products must, prior to their use, be specially mixed with other products of the same nature. For shelf-life reasons or product freshness it is often important for the mixing to be carried out just before use. This is particularly the case with chemical products in photographic processing. Customer requirements for easier handling of these photochemical bottles with less exposure to the chemicals has generated the need for a cap which does not need to be removed or replaced to dispense photochemicals. Seal integrity, customer handling, and recycleability has generated the need for a cap molded from high density polyethylene (HDPE) resin which can seal the bottle and be opened simply by inserting the bottle into processing apparatus. At the present time, each product forming part of such a combination is stored in a plastic flask closed by a liquid tight stopper. The photochemical manufacturing community currently utilizes various methods for sealing bottles filled with photographic development chemicals which includes, but is not limited to: 1) foam/cardboard seal insert inside the bottle cap; and 2) aluminum foil seal welded over the bottle neck opening and covered with a cap. A shortcoming of the aforementioned sealing methods is that they each present a propensity to leak that detracts or prevents recycling of the bottle without removing the cap and seal residue.
Another currently available practice for sealing a flask used in the photochemical manufacturing community includes a bottle cap with an integral bottleneck seal and segmented lid section. The cap provides a reliable fluid seal while the segmented lid is rupturable by blades available on existing photographic processing apparatus that tear or rupture the segmented portion of the cap. The aforementioned stopper design utilizes a tear channel or weakness with a rectangular cross section to bisect half of the frangible lid.
While the above cap meets the bottle seal requirements and recycling requirements, it is generally known in the photochemical community that a rather significant shortcoming is the puncturability of the segmented lid. Skilled artisans will appreciate that the downward force (average puncture force of 30.12 lbs. or 134.5 Newtons) required to puncture the segmented lid is beyond the physical capabilities of the average person.
Therefore, a need persists in the art to remedy the aforementioned shortcomings by requiring lower puncture forces while maintaining an inexpensive emptying method, as well as complete recycleability of the flask and closure.